package HashText;

import org.w3c.dom.Node;

import java.util.HashMap;
import java.util.Map;
import java.util.Random;

class Solution {
    class Node {
        int val;
        Node next;
        Node random;

        public Node(int val) {
            this.val = val;
            this.next = null;
            this.random = null;
        }
    }

    public Node copyRandomList(Node head) {
        if(head == null) {
            return null;
        }
        Map<Node,Node> map = new HashMap<>();
        Node cur = head;
        while(cur != null){
            map.put(cur,new Node(cur.val));
            cur = cur.next;
        }
        cur =head;
        while(cur != null){
            Node copy = map.get(cur);
            if(cur.next != null){
                copy.next = map.get(cur.next);
            }
            if(cur.random != null){
                copy.random = map.get(cur.random);
            }
            cur = cur.next;
        }
        return map.get(head);
    }
}
